Panel form with flexible cap holding access box in sealing relationship

ABSTRACT

A skeleton structure to be embedded in a prefabricated panel of concrete so that electrical wires can subsequently be installed in the panel. A hollow access box having an open side is positioned in the form in which the panel is to be poured so that the open side faces the peripheral wall of the form in close proximity thereto. At least one hollow conduit is also positioned in the form and communicates with the interior of the access box. A cap shaped sealing member of resiliently flexible material is securable to the peripheral wall of the frame and extends sealingly into the open side of the hollow access box to prevent intrusion of the liquid concrete into the interior of the access box as well as to maintain the latter in predetermined position relative to the peripheral wall of the form during hardening of the concrete.

United States Patent Bassani 3,680,826 45 Aug. 1,1972

I541 PANEL FORM WITH FLEXIBLE CAP HOLDING ACCESS BOX IN SEALING RELATIONSHIP [72] .lnventor: Ermanno Bassani, Corso di Porta Vittoria, 9, Milan, Italy [*1 Notice: The portion of the term of this patent subsequent to Feb. 1, 1988,

has been disclaimed.

22 Filed: Jan.24, 1966 [21] Appl. No.: 522,539

[30] Foreign Application Priority Data Jan. 25, 1965 Italy ..614 A/65 April 12, 1965 Italy ..3423 A/65 Jan. 4, 1966 Italy ...l3070 A/66 521 US Cl. ..249/91, 249/177, 425/3 51 Int. Cl. ..B28b 23/00 [58] Field at Search ..25/128 E, 128 K, 1 M, 2;

249/177, 184, 147, 142, 150,175, 176, 91, 83; 425/3; l8/DIG. 33

[56] References Cited UNITED STATES PATENTS 1,391,988 9/1921 Zents. ..249/184 X 1,530,200 3/1925 Richardson et al. ..25/128 E UX 1,653,251 12/1927 Boyton ..25/128 E UX 1,675,942 7/1928 Lundberg ..25/128 E UX 1,828,876 10/1931 Rohn ..25/128 E UX 2,286,564 6/1942 Newell ..249/177 2,424,835 7/1947 Luckey et a1. ..l8/D1G. 33 2,524,737 10/1950 Sawyer l8/D1G. 2,694,847 1 1/1954 Christiansen ..249/ 177 7/1956 Schafer et al ..249/184 2,775,017 12/1956 McDough ..25/128 E X 2,794,233 6/1957 Morton et a1. ..249/13 X 3,048,911 8/1962 Almon ..'....25/l28 K X 3,154,833 11/1964 'Kimball ..l8/D1G. 33 3,148,433 9/1964 Carriker ..249/177 X 3,157,966 11/1964 Sherburne ..249/177 X 3,166,816 1/1965 Berg ..249/177 3,170,216 2/1965 Neese ..249/177 3,313,515 4/1967 Mullen ..25/128 K 1,530,200 3/1925 Richardson et al. ..25/128 E UX 1,757,196 5/1930 Jaques ..25/128 E X 1,765,156 6/1930 Healy ..249/177 2,524,744 10/1950 Zevely ..249/176 2,684.5 I 8 7/1954 Whitlock ..249/177 X Primary ExaminerRobert D. Baldwin Attorney-Michael S. Striker [57] ABSTRACT A skeleton structure to be embedded in a prefabricated panel of concrete'so that electrical wires can subsequently be installed in the panel. A hollow access box having an open side is positioned in the form in which the panel is to be poured so that the open side faces the peripheral wall of the form in close proximity thereto. At least one hollow conduit is also positioned in the form and communicates with the interior of the access box. A cap shaped sealing member of resiliently flexible material is securable to the V eripheral wall f the fr me and extends sealingly into he open side 0 the ho ow access box to prevent 1ntrusion of the liquid concrete into the interior of the access box as well as to maintain the latter in predetermined position relative to the peripheral wall of the form during hardening of the concrete.

10 Claims, 28 Drawing Figures PATENTED 119?? 3.680.826

' SHEET 1 or 5 I 5 I '1.- Q 55 k9 INVENTOR Erm 4on0 Beam PATENIEB 1'97? 3.680.826 sum 2 0F 5 INVENTOR ATTORNEY PATENTEU 9 1 I972 SHEET 3 (IF 5 TVENTOR Y PATENTED 11973 3.680.826

sum u 0F 5 INVENTOR PATENTEDAUB 1 1912 3.680.826

sum 5 OF 5 PANEL FORM WITH FLLE CAP HOLDING ACCESS 80X IN SEALING RELATIONS This invention has for its object the provision of equipment for the formation of hollow passages and recesses in prefabricated panels for the construction of buildings, in order to enclose the electric power distributing structure within the walls and ceilings of the rooms of the building.

It is known that prefabricated main elements of buildings, such as walls and ceilings, are nowadays are prepared in manufacturing shops by casting reinforced or non-reinforced concrete into molds or casings, and are then transported to building site in order to be set in place for the construction of the ceilings and separating walls of the rooms. With the technique of prefabricating said elements a problem has to be solved, namely how to enclose the electric power system for lighting and other purposes, so as to supply electric current to domestic, medical, and the like appliances, instruments, small machinery for the kitchen, etc. In other words, it is desired to enclose in said prefabricated panels the electric conductors, lines, controlling devices, deriving and distributing boxes, insulating pipes for the protection of the wires, switches, fuses, signaling bells, and so on.

According to a known technique, the incorporation of said electric devices and material is effected during the formation of the prefabricated elements or panels by disposing the boxes, pipes and the like in the mold together with the iron wires or rods for reinforcing the concrete the and then of casting of the liquid cement or concrete itself into the mold.

However, during the casting operation of the liquid cement or concrete said derivation boxes and the insulating pipes are displaced by the forces created by the hydrostatic action of the concrete, especially in the case of vertical molds, and by the lateral throw provided by such forces.

Still another problem to be solved is how to prevent the liquid cement or concrete from entering and obstructing the inside of said hollow recesses and the like passages either totally or partially, which would prevent or make difficult the introduction thereinto of the electric wirings and other electric controlling means. This risk, the entry of the liquid cement, exists not only for said derivation boxes in their position on the bottom of the molding casing, but also inthe locations where said boxes are joined with said protecting pipes for the electric wires, and particularly at the positions of exit from said passages and recesses at the narrow sides or edges where the prefabricated elements are to be joined together.

According to the known art, in some cases it is the custom to fix the derivation boxes at the bottom of the casing by means of bolts which traverse said bottom. This solution does not solve the problem of how to avoid the penetration of the concrete into the recesses, and further requires that the casing be provided with the apertures for the bolts, so that such casing cannot be used further for the manufacture of differently made prefabricated elements. There is further the drawback to be solved the same consisting thereof that the boxes to be enclosed cannot be adapted to molding casings made of different materials, that is to say that boxes used with iron casings for instance cannot be used with wooden or cement casings.

The equipment subject matter of this invention solves efficiently the problem of anchoring the derivation boxes of electric plants in prefabricated elements or panels, and also eliminates any risk of entry of liquid cement or concrete into the hollow passages and recesses in said panels. It further solves the problem of the obstruction of the passage outlets at the narrow sides of the panels, so that the same will be fully free of obstruction whatever. The invention also affords the possibility to ensure a perfect disposition for the incorporation of the hollow means into the concrete, further enabling the use of whatever kind of molding casing, in-

dependently of, the material of which they are manufactured.

According to this invention, the derivation boxes and other means which have to be located on the walls of the casing are fastened by means of intermediate organs in the form of elastic caps, or the like, entirely hollow and leaning against the resting surface of the molding casing. The derivation boxes are placed onto said caps and frictionally retained thereon, due to the fact that said caps are internally provided with engaging organs for fastening to the wall of the casing, said organs being made of different materials according to the material of which the casing itself is manufactured.

The elastic caps are further provided with an annular step which acts as a sealing ring in respect of the box or other hollow body associated with the caps, thus impeding the infilatration of liquid concrete.

The connection between the boxes or other hollow accessories and the pipes is obtained throught connecting pieces of flexible material which ensure a tight seal. These pieces are fixed to entry holes of the boxes, and locked around the pipes so that here, also there is no possibility of the entry of cement or concrete.

The engaging organs by which the caps engage the wall of the casing are conceived so that the engagement will take place in the most rapid manner, thus facilitating and accelerating the work of preparing the devices and objects which are to be incorporated into the cement or concrete.

The invention further provides special means for shaping the outlet of the insulating pipes where the same extend from the narrow sides or edges of the prefabricated panels. Such means also is to be fastened through intermediate tight caps, and affords a quick and easy coupling of the pieces between contiguous panels at the time of installation of the electric plant.

The object of this invention is hereunder described in more details and in connection with the herewith attached drawings with reference to an example of embodiment which is not to be considered limiting.

Of said drawings;

FIG. 1 illustrates an embodiment of a room built with prefabricated panels as per the invention, and including recesses for the installation of the electricity distributing recesses for the installation of the electricity distributing plant;

FIGS. 2 and 3 refer to the step of disposing the hollow means to be enclosed within the concrete, in the interior of a molding casing; I

FIGS. 4 and 5 represent special derivation or distribution boxes used in the concrete of prefabricated panels;

FIG. 6 shows in an axial section the mode of fixing and coupling a derivation box as per this invention in the particular case of a horizontal molding casing made of iron;

FIG. 7 represents in cross section another mode of fixing a derivation box particularly used in the case of vertical or horizontal casings made of concrete or the like;

FIGS. 8 and 9 refer to two methods of fixing a cap for casings either horizontally or vertically;

FIG. lit) refers to a further fixing made of a cap for casings used either horizontally or vertically;

FIG. I I shows a fixing mode of a derivation box to be enclosed within the panel in a vertical casing;

FIG. 12 represents a further form of cap used for fixing said derivation boxes;

FIG. 13 illustrates the fixing mode of a derivation box in order to obtain a hollow passage in a wall, more particularly to be used in horizontal molds;

FIG. 14L shows another form of derivation box in order to obtain a hollow passage of variable length;

FIG. 15 refers to organs provided for affording outlets of pipes in the narrow sides of prefabricated panels or plates;

FIGS. 16 and 117 how methods of protection for the pipes in order to prevent the entry of extraneous materials or articles;

FIG. 18 is a particular form of flexible pipes, to be used in the installation with prefabricated panels;

FIGS. 19, 2t) 21 show a tool used for the extraction of rubber caps from the recesses in prefabricated panels, and the method of using the tool;

FIGS. 22 and 23 represent the position taken by the derivation boxes enclosed within the panel, and by the pipes of a finished prefabricated panel;

FIG. 24 shows a occluding organ for the hollow recesses of a finished prefabricated panel having the purpose of preventing the introduction thereinto of extraneous materials;

FIG. 25 represents the coupling system between prefabricated panels composing a ceiling of the room and prefabricated panels composing a contiguous wall of the same room;

FIG. 26 refers to a method of composing a coupling organ between a vertical wall and a correspondent ceilmg;

FIG. 27 shows a method of coupling simultaneously two ceilings and consecutive walls; and

FIG. 28 shows of an enclosed derivation box in order to obtain a lighting center.

In FIG. I there is indicated an apartment room in general, being composed of the walls ll, 2 and 3 and of a ceiling 4 and built with prefabricated panels or plates as per the invention. Within said panels or plates there are enclosed derivation or containing boxes and the corresponding pipes for the protection of the electric wirings, which are all accordingly incorporated within the concrete forming any single panel. Thereby a lighting center is obtained, to which a protecting pipe 6 provides the connection from the exterior to said center and encloses the electric line for feeding electric power to said center. From the last, several other pipes 7, 8 and 9 depart in order to permit coupling with further corresponding pipes 7 S and 9 which are respectively located in the walls ii, 2 and 3, are which in turn reach further derivation boxes 10, ll and 12, respectively, from which still further pipes 13 may derive in order to connect secondary derivation or containing boxes 14. Through these pipes electric as wires are introduced for the connection of the derivation boxes and other recesses wherein the electric signalling or controlling devices will be enclosed, such as switches, commutators, fuses, sockets, bell-button and the like.

The incorporated derivation or containing boxes can be cylindrical, square, rectangular in shape, according to the nature and number of electric or the like devices to be enclosed therein.

The panels for the walls I, 2 and 3, as well for the ceilings 4, for instance in their definitive sizes for erecting after the structure of the building is finished, are prefabricated in a manufacturing shop. As shown in FIG. 2, a metallic reinforcing net of iron wires or rods 116 is positioned in a mold in combination with the derivation or containing boxes l7 and the insulating and the protecting pipes lltB, which latter also can depart from said boxes for the connection with further boxes or terminate at their end portions against the lateral walls of casing 115.

The box I7 must be held strongly on the bottom of the mold, so as to be not displaced or lifted upon the occurrence of stresses due to the hydrostatic throw caused by the concrete which tends to throw upwards any object it contacts upon pouring into the mold, and due further to the lateral forces generated acting upon the concrete by the sides of the mold.

As shown in FIG. 3, the pipes it can be easily fixed to the round-irons T6 of the metallic net by means of fastening metallic bands 2t).

FIGS. 2 and 3 and respectively 4 and 5 refer to containing boxes of circular shape, it being evident that other shapes for may be adopted.

Independently of their shape, boxes 17 the as in FIG. 41, may be made with their lower part 211 restricted in the direction of their opening and with their upper part 22 having inclined surfaces. Such boxes are particularly well adapted for the case wherein the protecting pipes have to be bent in order to connect with the boxes, as in the case of FIG. 23 which comprises a prefabricated ceiling panel provided with such squeezed portions as enable it to obliquely combine with a box 17. The inclined wall 22 of said box allows a very small bend in the pipes.

Boxes as in 24 at FIG. 5 may be provided having an upper cylindrical part 25 and a lower restricted part 26 directed towards the outlet.

The boxes are usually manufactured without holes, which will be bored at the time of setting-up in the net of the panels in order to avoid that non-used holes remain at the installed box.

As shown in FIG. 41, a box to be enclosed into the panel, in the case it should be used to compose a lighting center, will be equipped with an upper transversal supporting hook 23, which will remain incorporated within the concrete, thus resisting whatever stress tends to extract said box from its embedded position in the concrete, as for instance when a heavy chandelier is suspended from it. As represented in FIGS. 6 and '7, the hook 28 penetrates the internal portion of a collar 29 of said box through a small threaded cylinder 30, which projects into the interior of said box, where it is fixed by means of a border 31 provided with an eyelet.

As shown in FIGS. 5, 6 and 7, the pipes 18, which have to be connected to the holes 27 of the boxes, are fastened by means of a coupling element 32. This element is made of an elastic or flexible material, for instance rubber, having a front portion 33 of larger diameter and provided with an annular groove 34, wherein the border of a hole 27 engages, after the portion 33 has been introduced in the last. The coupling means 32 further comprises a rear cylindrical projection 35 directed to the interior, a pipe 18 being inserted therein and fastened under tight connection by means of an elastic locking ring 36. As shown in said figures, the coupling means 32 ensures a highly tight closure both in correspondence with the hole of the box, and in the zone of insertion of the pipe, so as to prevent any entry of concrete thereinto.

For fixing the containment boxes to the bottom of the mold an intermediate means is used; the same is composed of a cap 37 made of flexible material, e.g., rubber. Said cap 37 is hollow in its interior, and has along its border an annular step 38 projecting outwards, by means of which it rests on the bottom 39 of the mold.

the mold used.

In case the mold is made of iron, as in FIG. 6, the engaging element is composed of a permanent magnet 42 surrounded by a block 43 of magnetic material and fixed to the cap by means of a bolt 44. The height of said permanent magnet 42 is such that a small space 42' remains between it and the bottom of the mold, so that the attraction stress still can deform the cap by holding it strongly pressed with its borders against said bottom. One will thus have the certainty that the border of the cap is conveniently pressed against the bottom 39 over its whole circumference, thus ensuring an appropriate tight closure which prevents any entry of concrete. Furthermore, step 38 serves with respect to the border or edge of the box 17 function of a packing means which is inserted on said cap, so that entry of concrete also cannot take place to the interior of the box.

The embodiment of FIG. 7 is the same as that of FIG. 6, with the only variant that the permanent magnet 42 is provided with an axial blind hole 45 that faces another blind hole 46 bored in the bottom of the mold, 50 that a pin 47 can be introduced into both these blind holes 45 and 56 with the purpose of impeding any dis placement of the cap when the box is subjected to strong lateral forces, as, e. g., in the case of vertical casings or molds wherein the bottom of the mold is disposed vertically and the concrete is cast into the mold through an upper opening of the same.

Still in the case of FIG. 7, there is considered the use of a casing 48 made of concrete or the like. In this case, an iron plate 49 will have to be incorporated in the casing 43 at a location where a box is to be positioned, in order to ensure the correct attraction of the permanent magnet 42. Said iron plate 49 is provided at its lower portion with a collar 50 in order to reinforce its anchoring in the casing 48.

FIG. 8 refers to wooden casings.

In this case, cap 37 is fixed by means of a wood-screw 51, which will be introduced through a hole 52 with which the cap is provided, and then screwed into the wooden bottom of the casing as at 53.

FIG. 9 also refers to wooden molds or casings, with the difference that a simple nail 54 is used in place of the wood-screw 51.

In the case of wooden casings or molds, also, there exists the possibility to use a permanent magnet as in 42 to fasten the cap, provided an iron plate is set at the bottom of such mold in order to ensure the attraction of said magnet. Said iron plate of course will be set in the same manner as shown in FIG. 7, wherein the iron plate $7 is illustrated.

FIG. Ml concerns an embodiment particularly adapted for fixing of a cap in vertical molds. Herein, cap 37 is locked by means of a bolt 5s and a nut 57. At its lower portion the bolt has a shaft 55 provided at its lower part with a throat 58, with a view toward cooperation with a head 59 of a screw 60v threaded into the bottom 61 of said mold. There is thus ensured a correct and strong locking of the cap, preventing any displacement of it. Said bolt portion 55 is made of a breakable material so that, after the solidification of the concrete has taken place, on extraction of the panel from the mold the bolt portion will break just at its restricted portion 58, the part 60 of said bolt remaining in place and thus closing the respective hole in the bottom 61, although it may be removed for the application of another or successive cap, for instance.

The cap shown in FIG. 12 is of the same kind as the one of FIGS. 6 and 7, with the only difierence that bolt 44 is tightened by an appropriately flattened nut 62, which is fixed to the cap through projections 63, ensuring a strong pression against the rubber mass of cap 37. Such a cap is usable for boxes of lesser height.

FIG. 11 represents a further variant for use with vertical molds. In this case, box 17 is yet fixed by means of cap 37 which may be provided, e.g., with an attracting permanent magnet. At its exterior the box 17 has a pin 64 which is coaxially disposed in respect of cap 37, and the end of which is pointed as in 65 to conveniently press against the mobile wall 66 of the mold, opposed to the fixed wall 68 of the same, on which the box 17 rests. The pressure of pin 65 can be obtained by making use of the elasticity of the box 17.

FIG. 13 illustrates a box 69 provided to form a traversing passage through a wall and comprises a lower entrance or outlet 70 and an upper outlet or entrance 71, respectively. This box should be provided with holes, into which coupling means 32 will be introduced in order to provide therein for the anchoring of the protecting and insulating pipes. Box 69 is fixed by means of a cap 37 to the bottom of the mold or casing, in the same manner as for the other boxes, while the upper opening or mouth 71 is closed by a covering plate 72 which prevents the entry of concrete.

FIG. I4 refers to a variant of FIG. 113, in the sense that the telescopically box is made of two parts 73 and 74, which are coupled to one another. Such a box may be locked as already shown in FIG. I3 for the case of horizontal molds, or as in FIG. 1141 for the case of vertical casings. Both openings thereof are locked by means of the cap 37. Both parts 73 and 74 of the box 69 may be lenghtened or shortened in accordance with the thickness of the respective prefabricated panels or plates or walls.

FIG. shows the anchoring of terminal parts of the pipes reaching the edges or narrow sides of the panels. In this case a hollow member 75 in the shape of a funnel having a frontal cylindrical part 76 of larger diameter inserted in a cap 37, which may be locked to the lateral wall 77 of the casing or mold, as per one of the methods reported in FIGS. 6 through I2, and in accordance with the material composing said wall. At its rear portion the element 75 comprises a second cylindrical component 78 of lesser diameter, provided with an internal collar 79, whereupon the annular groove 89 of a coupling organ 81 engages in order to connect said element 75, thus tightly sealing this connection. The member SI has at its rear end a cylindrical tail 8 whereon a pipe III is inserted and sealed by means of an elastic ring 83.

In its interior, the member fill is provided with a countersunk opening 84 with the purpose to render easy the passage of the rounded end of a tool serving to pull the electric wirings through the protecting and insulating pipes of the prefabricated panels. Having effected the casting operation of the concrete and, after the solidification of it, having also provided for the extraction of the thus prefabricated panel from the mold, a large hole will exist on the edge or narrow side'of the panel, in correspondence with a similar hole at the edge or narrow side of a consecutive panel used to compose e.g. two ceilings and two consecutive walls, as illustrated in FIG. 27. These facing holes will be wide enough to assure the easy passage of the electric wires at the time of installation of the electric plant, even if the panels should not be exactly in registry with one another.

FIGS. 16 and I7 refer to a protecting method for the insulating pipes enclosing the electric wirings by means of metallic coverings $5, in the form of two or more metallic appropriately inclined shields 86 and 87 which are used to prevent a nail forced into the wall or ceiling from breaching the insulating pipes and coming in contact with the electric wires enclosed within the same this could cause shortcircuiting or like inconveniences.

The shields S6 and 87 deflect such a nail.

FIG. I8 illustrates the form of pipe used, which is composed of a series of annular undulations or corrugations 88 ensuring a sufficient flexibility of the pipe without any reduction of the internal cross section thereof in the zones where the same is bent. Corrugations 88 further impart to the pipe an adequate resistance to squeezing. Said pipes, generally speaking, will be made of a material of sufiicient mechanical and thermal strength. The preferred material is polypropylene appropriately treated.

FIGS. I9, 20 and 21 represent a tool for the extraction of the rubber caps 37, after the concrete is solidified, from the derivation or containing boxes which will remain incorporated within the prefabricated panels or walls. This tool is composed of a handle 89 on an end support 90, and provided in its intermediate portion with an iron plate 911, which is suspended from said handle via a pin 92 pivotable about a hinge 93 (FIG. 29). Said tool is disposed on the prefabricated panel as shown in FIG. 20 so that the plate 9H rests on the permanent magnet enclosed within the cap. Now exerting a pulling force upon said handle 89, and provided that the last is turned around the resting position 99, a strong pulling force is exerced upon the magnet, thus efiecting its extraction together with the cap, which both will become disengaged from the box, as shown in FIG. 2. On said handle 89 a lever 94 may be applied, of which one end will traverse a split 95 of the disc 91, while the other end bears underneath the rear end of handle 89. This lever also will serve to unlock the permanent magnet from the disc 91 by urging said lever against the handle 89 so as to cause the insertion of the front portion 96 over the split 95 thus causing the detachment of the permanent magnet.

FIGS. 22 and 23 refer to the case of utilization of boxes of the kind shown in FIG. 5, wherein the pipes I7 connected with the same are always in horizontal position.

FIG. 24 represents a cover 97 which may be used to occlude all recesses of a prefabricated panel so as to avoid any penetration of extraneous materials into said recesses and hollow passages in the panels during transport and stocking.

FIG. 25 illustrates the connection between a ceiling 98 as per the invention and a corresponding wall 99 set edge by edge. In this case, the recesses are connected with one another by means of a pipe MM) provided with elements lltlil to be inserted into the internal of said recesses 75.

FIG. 26 shows the case of the connection between a prefabricated ceiling W2 according to the invention and a wall 193 of the same kind the last being set in an intermediate position. In this case, in the ceiling 102 a box as represented in FIG. 4 or 5 will be used, while for the wall 193 a box I94 is adapted, this one presenting a double entrance means, viz.: a mouth piece I facing the edge of the wall and directed upwards, and a mouth piece I06 the opening of which is directed laterally and can be used as a derivation box. Of course, the box M4, in order to permit casting of the concrete into the mold, will be fastened to the mold itself by means of two caps of the already illustrated kind, and respectively inserted in the mouths I05 and M16.

FIG. 29 shows a method according to which the box I7 is provided with a supporting plate 28 for attaching thereto a hook I97 for supporting a chandelier. To this end, said hook MP7 is prolonged upwardly by means of a threaded shaft to be screwed in the small cylindrical element 30) supported by the box, and eventually surrounded by a rotatable sleeve I98. Said box is closed by a cover I99 provided with an intermediately disposed bore permitting the passage of the hook 1107.

The hereabove described equipment not only solves correctly the problem of fastening hollow means to incorporate in concrete of prefabricated panels, plates, walls or ceilings in one or more elements, and of avoiding any risk of entry of the concrete into the according recesses, hollow passages, derivation boxes, protecting pipes and the like, but also ensures quick, easy, ad-

vantageous and economical operations for the manufacture of the said prefabricated panels and the like.

What is claimed is:

1. Arrangement for forming a skeleton wiring structure in prefabricated panels made from hardenable material which is introduced in flowable state into a form having a peripheral wall, comprising in combination, at least one hollow access box having an open side and arranged in predetermined position within the form with said open side facing said peripheral wall of the form in close proximity thereto; at least one hollow conduit positioned in the form and communicating with the interior of said access box so that wiring may be inserted into an withdrawn from said conduit through said open side of said access box; and sealing means including a cap member of resiliently flexible material frictionally connected with said access box in sealing relationship therewith, said sealing means also being connectable with the peripheral wall of the form and sealingly and releasably extending into said open side for preventing entry to the interior of said access box of said hardenable material while the same is in flowable state, and for maintaining said access ,box in predetermined position during the flowable state of said hardenable material.

2. An arrangement as defined in claim 1; and further comprising a sealing bead provided on said cap member for sealing said access box against entry of said material when said cap member extends into said open side of said access box.

3. An arrangement as defined in claim 1; further comprising cooperating sealing ribs respectively provided on said access box and said cap member and sealingly engaging with one another when said cap member extends into said open side of said access box.

4. An arrangement as defined in claim 1, said access box being substantially funnel-shaped and having a converging side opposite said open side, said converging side being provided with an opening communicating with the interior of said access box and for receiving one of said open ends of said coupling member.

5. An arrangement as defined in claim 1; said sealing means further comprising releasable connecting means for releasably connecting said cap member with the peripheral wall of said form.

6. An arrangement as defined in claim 5, wherein said peripheral wall of said form consists at least in part of magnetizable material; said connecting means including a permanent magnet connected with said cap member and arranged for magnetically connecting the same to said peripheral wall of the form.

7. An arrangement as defined in claim 5, said connecting means including a pin member having opposite end portions respectively extending into apertures provided in said cap member and the peripheral wall of the form for maintaining said cap member against lateral displacement relative to the peripheral wall.

8. An arrangement as defined in claim 5, said connecting means including a fastener member extending through said cap member into said peripheral wall of the form.

9. An arrangement as defined in claim 5, said fastener member being a bolt having a weakened zone along which it may be severed during separation of the finished panel and the form.

10. An arrangement for forrmng a skeleton wiring structure in prefabricated panels made from hardenable material which is introduced in flowable state into a form having a peripheral wall, comprising in combination, at least one hollow access box having an open side and arranged in predetermined position within the form with said open side of said access box facing said peripheral wall of the form in close proximity thereto; at least one hollow conduit positioned in the form and communicating with the interior of said access box so thatwiring may be inserted into and withdrawn from said conduit through said open side of said access box; sealing means including a cap member of resiliently flexible material frictionally connected with said access box in sealing relationship therewith, said sealing means also being connectable with the peripheral wall of the form and sealingly and releasably extending into said open side for preventing entry to the interior of said access box of said hardenable material while the same is in flowable state, and for maintaining said access box in predetermined position during the flowable state of said hardenable material; said coupling means for sealingly coupling said conduit and said access box, said coupling means comprising a tubular coupling member of flexible material having opposite open ends respectively communicating with the interior of said access box and said conduit. 

1. Arrangement for forming a skeleton wiring structure in prefabricated panels made from hardenable material which is introduced in flowable state into a form having a peripheral wall, comprising in combination, at least one hollow access box having an open side and arranged in predetermined position within the form with said open side facing said peripheral wall of the form in close proximity thereto; at least one hollow conduit positioned in the form and communicating with the interior of said access box so that wiring may be inserted into an withdrawn from said conduit through said open side of said access box; and sealing means including a cap member of resiliently flexible material frictionally connected with said access box in sealing relationship therewith, said sealing means also being connectable with the peripheral wall of the form and sealingly and releasably extending into said open side for preventing entry to the interior of said access box of said hardenable material while the same is in flowable state, and for maintaining said access box in predetermined position during the flowable state of said hardenable material.
 2. An arrangement as defined in claim 1; and further comprising a sealing bead provided on said cap member for sealing said access box against entry of said material when said cap member extends into said open side of said access box.
 3. An arrangement as defined in claim 1; further comprising cooperating sealing ribs respectively provided on said access box and said cap member and sealingly engaging with one another when said cap member extends into said open side of said access box.
 4. An arrangement as defined in claim 1, said access box being substantially funnel-shaped and having a converging side opposite said open side, said converging side being provided with an opening communicating with the interior of said access box and for receiving one of said open ends of said coupling member.
 5. An arrangement as defined in claim 1; said sealing means further comprising releasable connecting means for releasably connecting said cap member with the peripheral wall of said form.
 6. An arrangement as defined in claim 5, wherein said peripheral wall of said form consists at least in part of magnetizable material; said connecting means including a permanent magnet connected with said cap member and arranged for magnetically connecting the same to said peripheral wall of the form.
 7. An arrangement as defined in claim 5, said connecting means including a pin member having opposite end portions respectively extending into apertures provided in said cap member and the peripheral wall of the form for maintaining said cap member against lateral displacement relative to the peripheral wall.
 8. An arrangement as defined in claim 5, said connecting means including a fastener member extending through said cap member into said peripheral wall of the form.
 9. An arrangement as defined in claim 5, said fastener member being a bolt having a weakened zone along which it may be severed during separation of the finished panel and the form.
 10. An arrangement for forming a skeleton wiring structure in prefabricated panels made from hardenable material which is introduced in flowable state into a form having a peripheral wall, comprising in combination, at least one hollow access box having an open side and arranged in predetermined position within the form with said open side of said access box facing said peripheral wall of the form in close proximity thereto; at least one hollow conduit positioned in the form and communicating with the interior of said access box so that wiring may be inserted into and withdrawn from said conduit through said open side of said access box; sealing means including a cap member of resiliently flexible material frictionally connected with said access box in sealing relationship therewith, said sealing means also being connectable with the peripheral wall of the form and sealingly and releasably extending into said open side for preventing entry to the interior of said access box of said hardenable material while the same is in flowable state, and for maintaining said access box in predetermined position during the flowable state of said hardenable material; said coupling means for sealingly coupling said conduit and said access box, said coupling means comprising a tubular coupling member of flexible material having opposite open ends respectively communicating with the interior of said access box and said conduit. 